Department of Bone and Joint Surgery, the Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710004, Shanxi, China.
State Key Laboratory for Mechanical Behavior of Materials, School of Materials Science and Engineering, Xi'an Jiaotong University, Xi'an, 710049, Shanxi, China.
Biomed Eng Online. 2020 Feb 18;19(1):12. doi: 10.1186/s12938-020-0755-x.
Bone defects are often combined with the risk of infection in the clinic, and artificial bone substitutes are often implanted to repair the defective bone. However, the implant materials are carriers for bacterial growth, and biofilm can form on the implant surface, which is difficult to eliminate using antibiotics and the host immune system. Magnesium (Mg) was previously reported to possess antibacterial potential.
In this study, Mg was incorporated into poly(lactide-co-glycolic acid) (PLGA) to fabricate a PLGA/Mg scaffold using a low-temperature rapid-prototyping technique. All scaffolds were divided into three groups: PLGA (P), PLGA/10 wt% Mg with low Mg content (PM-L) and PLGA/20 wt% Mg with high Mg content (PM-H). The degradation test of the scaffolds was conducted by immersing them into the trihydroxymethyl aminomethane-hydrochloric acid (Tris-HCl) buffer solution and measuring the change of pH values and concentrations of Mg ions. The antibacterial activity of the scaffolds was investigated by the spread plate method, tissue culture plate method, scanning electron microscopy and confocal laser scanning microscopy. Additionally, the cell attachment and proliferation of the scaffolds were evaluated by the cell counting kit-8 (CCK-8) assay using MC3T3-E1 cells.
The Mg-incorporated scaffolds degraded and released Mg ions and caused an increase in the pH value. Both PM-L and PM-H inhibited bacterial growth and biofilm formation, and PM-H exhibited higher antibacterial activity than PM-L after incubation for 24 and 48 h. Cell tests revealed that PM-H exerted a suppressive effect on cell attachment and proliferation.
These findings demonstrated that the PLGA/Mg scaffolds possessed favorable antibacterial activity, and a higher content of Mg (20%) exhibited higher antibacterial activity and inhibitory effects on cell attachment and proliferation than low Mg content (10%).
在临床中，骨缺损常伴有感染风险，常植入人工骨替代物来修复缺损的骨骼。然而，植入物材料是细菌生长的载体，在植入物表面会形成生物膜，这很难通过抗生素和宿主免疫系统来消除。镁（Mg）此前被报道具有抗菌潜力。
在这项研究中，将 Mg 掺入聚（乳酸-共-乙醇酸）（PLGA）中，使用低温快速成型技术制造 PLGA/Mg 支架。所有支架分为三组：PLGA（P）、Mg 含量较低的 PLGA/10wt%Mg（PM-L）和 Mg 含量较高的 PLGA/20wt%Mg（PM-H）。将支架浸入三羟甲基氨基甲烷-盐酸（Tris-HCl）缓冲溶液中，通过测量 pH 值和 Mg 离子浓度的变化来进行支架的降解测试。通过平板法、组织培养板法、扫描电子显微镜和共聚焦激光扫描显微镜研究支架的抗菌活性。此外，通过使用 MC3T3-E1 细胞的细胞计数试剂盒-8（CCK-8）测定法评估支架的细胞附着和增殖。
Mg 掺入的支架降解并释放出 Mg 离子，导致 pH 值升高。PM-L 和 PM-H 均抑制细菌生长和生物膜形成，并且在孵育 24 和 48 小时后，PM-H 显示出比 PM-L 更高的抗菌活性。细胞试验表明，PM-H 对细胞附着和增殖有抑制作用。
这些发现表明，PLGA/Mg 支架具有良好的抗菌活性，较高的 Mg 含量（20%）比低 Mg 含量（10%）具有更高的抗菌活性和对细胞附着和增殖的抑制作用。
